Cassette tape player

ABSTRACT

A cassette tape player includes a cassette carrying mechanism which conveys a cassette tape between the insertion position and the hold position of the player automatically, a mode selection lever which reciprocates depending on various operational modes, and a drive motor which drives the cassette carrying mechanism and the mode selection lever, a lock mechanism which selectively prevents the movement of the mode selection lever or the cassette carrying mechanism, and a planetary gear mechanism coupled between the drive motor and the mode selection lever and the cassette carrying mechanism. The planetary gear mechanism includes a sun gear rotated by the drive motor, a ring gear which steadily meshes with one of a first rack provided on the mode selection lever and a second rack provided on the cassette carrying mechanism, and a carrier which steadily meshes with another of the first rack and second rack. The lock mechanism selectively prevents the movement of the mode selection lever or the cassette carrying mechanism so that the driving force of the drive motor applied to the sun gear is released from only one of the ring gear and the carrier. The cassette tape player is capable of driving the cassette carrying mechanism and the mode selection lever reliably and enables the cassette tape player to be compact.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cassette tape player, andparticularly to a drive mechanism which moves, with a single motor, thecassette carrying mechanism which conveys a cassette tape in the playerautomatically and the mode selection lever which switches an operationalmode of the player.

2. Description of the Prior Art

Cassette tape players for use in vehicles generally employ cassettecarrying mechanisms. The cassette carrying mechanism automatically loadsa cassette tape, which has been put halfway into the player, to thecassette hold position, and automatically ejects the cassette tape fromthe hold position. The cassette tape player further includes areciprocating drive mechanism for moving a mode selection leverdepending on the selected mode and a drive mechanism for rotating thereel bases in certain directions and at certain speeds depending on themode.

All of these mechanisms are driven by a single motor by operation ofidler gears provided between the motor and the drive mechanisms andassociated electromagnetic solenoids which operate the idler gears. Forexample, at loading or ejecting a cassette tape, a solenoid operates onthe idler gear between the motor and the cassette carrying mechanism totransmit the output torque of the motor to the cassette carryingmechanism.

However, a cassette carrying mechanism based on the operation of idlergears is likely to cause gear noise when an idler gear meshes withanother gear in the transmission mechanism, and to fail to engage anidler gear with another gear due to faulty operational timing.

A drive mechanism that overcomes these problems is disclosed in U.S.Pat. No. 5,105,320. The cassette tape player disclosed therein isdesigned to keep the motor drive gear engage with the rack of the modeselection lever which is linked to the cassette carrying mechanism by acam member. In operation, when the mode selection lever moves for acertain distance with the rotation of the Rotor, the cassette carryingmechanism performs the loading operation or ejecting operation throughthe cam member during the movement, and when the mode selection leverfurther moves an additional distance, another mechanism operates duringthe movement of the mode selection lever.

Although that conventional cassette tape player eliminates the gearnoise and faulty gear meshing by retaining the motor drive gear inengagement with the rack of mode selection lever, the rack that iscommonly used for moving the cassette carrying mechanism and othermechanisms must be very long, making the compact design of the cassettetape player difficult. Moreover, the cam member for driving the cassettecarrying mechanism must be disposed between the mode selection lever-andthe cassette carrying mechanism, resulting in a complex and costlymechanism.

SUMMARY

The present invention is intended to cope with the foregoing prior artshortcomings, and its prime goal is to provide a cassette tape playercapable of driving the cassette carrying mechanism and mode selectionlever noiselessly and reliably, and which also enables the drivemechanism to be compact.

To achieve this, the present invention is directed to a cassette tapeplayer having a cassette carrying mechanism which conveys a cassettetape between an insertion position and hold position of the player, amode selection lever which reciprocates depending on the operationalmode, and a drive motor which drives the cassette carrying mechanism andmode selection lever, where the player further includes a lock mechanismwhich selectively precludes the movement of the mode selection lever orcassette carrying mechanism, and a planetary gear mechanism locatedbetween the drive motor and the mode selection lever and cassettecarrying mechanism and which consists of a sun gear rotated by the drivemotor, a ring gear which steadily meshes with one of a first rackprovided on the mode selection lever a second rack provided on thecassette carrying mechanism, and a carrier which steadily meshes withanother of the first rack and second rack, the lock mechanism operatingselectively to preclude the movement of the mode selection lever orcassette carrying mechanism so that the driving force of the drive motorapplied to the sun gear is released from only one of the ring gear andthe carrier.

In operation, when the drive motor rotates, the rotation applied to thesun gear of the planetary gear mechanism is delivered selectively by thering gear or carrier as the output gear to the mode selection lever orcassette carrying mechanism. For example, during the cassette tapeloading or ejecting operation, the torque of the drive motor istransmitted only to the cassette carrying mechanism by way of one outputgear, and during FF (fast feed) or playback operation, the motor torqueis transmitted only to the mode selection lever by way of another outputgear.

The lock mechanism is switched depending on the rotational direction ofthe drive motor when the cassette tape is in the hold position of theplayer, and it precludes the mode selection lever from moving during theoperation of the cassette carrying mechanism or precludes the cassettecarrying mechanism from moving during the operation of the modeselection lever.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a cassette tape player based on an embodimentof this invention, in the state of the end of cassette tape ejection;

FIG. 2 is a plan view of the cassette tape player in the state of theend of cassette tape loading;

FIG. 3 is a side view of the cassette carrying mechanism of the cassettetape player, in the state of the end of cassette tape ejection;

FIG. 4 is a side view of the cassette carrying mechanism in the state ofthe end of cassette tape loading;

FIG. 5 is a plan view of the cassette tape player, with the cassettecarrying mechanism removed;

FIG. 6 is a plan view of the head base of the cassette tape player;

FIG. 7 is a plan view of the selection lever of the cassette tapeplayer;

FIG. 8 is a bottom view of the cassette tape player seen from the rearof the chassis;

FIG. 9 is a cross-sectional view of the reel base of the cassette tapeplayer;

FIG. 10 is a bottom view of the mode selection lever of the cassettetape player;

FIG. 11 is a plan view of the support plate of the cassette tape playerseen from the top;

FIG. 12 is a cross-sectional view of the torque transmission mechanismof the auxiliary motor of the cassette tape player;

FIG. 13 is a view of the planetary gear mechanism used in the torquetransmission mechanism;

FIG. 14 is a perspective view showing disassembled the principal partsof the torque transmission mechanism;

FIGS. 15A and 15B are views showing the switching operation of thetorque transmission mechanism, with FIG. 15A being the end of cassettetape ejection and FIG. 15B being the end of cassette tape loading;

FIG. 16 is a bottom view of the cassette tape player in its Pause mode;

FIG. 17 is a bottom view of the cassette tape player in its Normal Playmode;

FIG. 18 is a bottom view of the cassette tape player in its Reverse Playmode;

FIG. 19 is a bottom view of the cassette tape player in its Rewind (REW)mode;

FIG. 20 is a bottom view of the cassette tape player in its REW brakeoperation;

FIG. 21 is a bottom view of the cassette tape player in its Fast Feed(FF) mode;

FIG. 22 is a bottom view of the cassette tape player in its FF brakeoperation;

FIG. 23 is a flowchart showing the slack eliminating operation of thecassette tape player;

FIGS. 24A and 24B are waveform diagrams of the pulse signals produced bythe optical sensors during the slack eliminating operation;

FIGS. 25A and 25B are waveform diagrams of the pulse signals produced bythe optical sensors at the end of the slack eliminating operation;

FIG. 26 is a flowchart showing the FF and REW operations of the cassettetape player; and

FIG. 27 is a view of the reel base rotation detecting device of thecassette tape player.

DETAILED DESCRIPTION

An embodiment of this invention is explained with reference to thedrawings. FIGS. 1 through 14 show a flat chassis 1, on which is mounteda main motor 2 which rotates in one direction at a high speed or a lowspeed, an auxiliary motor 3 which rotates in both directions at aconstant speed, and a cassette carrying mechanism 4.

In FIGS. 1 through 4, the cassette carrying mechanism 4 includes twoside plates 5 and 6 fixed to the chassis 1, a slide plate 7 locatedoutside of one side plate 5, a plate base 8 supported rotatably betweenthe side plates 5 and 6, and a cassette holder 9 connected to one end ofthe plate base 8. The cassette carrying mechanism 4 is driven by theauxiliary motor 3.

The side plate 5 defines a guide hole 5a and two guide bosses 5b, andthe slide plate 7 defines a cam hole 7a and two long holes 7b. The slideplate 7 is supported slidable by the side plate 5. At the lower end ofthe slide plate 7, a block member 10 is fixed to the slide plate 7 bymeans of an extension spring 11, with a first rack 10a formed in theexternal surface of the block member 10.

Attached to the plate base 8 are a shaft 8a and a roller 8b. The shaft8a is fitted rotatably on the side plates 5 and 6, and the roller 8b isattached to run through the guide hole 5a of the side plates 5 andengage the cam hole 7a of the slide plate 7. The slide plate 7 on itsupper surface defines a long hole 7c and an L-shaped slit 7d, and a pin12 which runs through the long hole 7c is fixed on the upper surface ofthe side plates 5. A first ejection arm 13 and second ejection arm 14are pivoted on the pin 12. These ejection arms 13 and 14 are held at aconstant angle by means of a boss (not shown) and a extension spring 15,and a pin 14a which is fitted vertically on the second ejection arm 14engages with the slit 7d.

The first ejection arm 13 defines a cam hole 13a and a long hole 13b,and part of a detecting lever 16 engages the cam hole 13a. The detectinglever 16 is supported rotatably on the upper surface of the side plates5, and it confronts a cassette insertion detecting switch 18 mounted ona printed circuit board 17. A boss 19a of a slider 19 is inserted in thelong hole 13b of the first ejection arm 13, and it can move back andforth along a guide groove 8c formed on the upper surface of the platebase 8.

As shown in FIG. 5, a pair of capstan shafts 20 and 21 are supportedrotatably by bearings 22 and 23 on the surface of the chassis 1, and apair of pinch levers 24 and 25 are supported rotatably by pivots 26 and27. Pinch rollers 30 and 31 are supported rotatably by pivots 28 and 29on the pinch levers 24 and 25 so that the pinch rollers 30 and 31 comein contact with and move away from the respective capstan shafts 20 and21 in response to turning of the pinch levers 24 and 25.

On the chassis 1, there is placed a head base 32, which can reciprocateby being guided in the up/down direction of FIG. 5. A magnetic head 33is fixed on the head base 32, and a pin 34 is attained on the head base32. The pinch rollers 30 and 31 are spring-biased toward the capstanshafts 20 and 21 by means of a line spring 35 held by the pin 34.

The head base 32 has the shape of a square frame, in which is disposedtwo reel bases 36 and 37 and a selection lever 38. The selection lever38 is supported rotatably by a boss 1a which protrudes on the chassis 1,and it is coupled at the end with a selection arm 39 with a pin. Theselection arm 39 is located between the chassis 1 and the head base 32and supported rotatably by a pivot 40 on the chassis 1. A pin 41 fittedvertically on the selection arm 39 runs through the chassis 1 and exitsfrom its rear surface. Accordingly, when the selection arm 39 turns onthe pivot 40, the selection lever 38 turns on the boss 1a in thedirection opposite to the selection arm 39.

A pair of idler levers 42 and 43 are disposed between the chassis 1 andthe selection lever 38, and these idler levers 42 and 43 are supportedrotatably by the outer surface of the bearings 22 and 23. The idlerlevers 42 and 43 each define at one end the cam holes 42a and 43a (seeFIG. 8) and pivots 44 and 45 are fitted vertically on the other ends ofidler lever 42 and 43. These pivots 44 and 45 run through holes formedin the chassis 1 and exit from its rear surface. On the chassis 1, thereis pivoted a type identifying lever 46 for identifying the type ofcassette tape T, and part of the lever 46 runs through the chassis 1 andexits from its rear surface.

As shown in FIG. 6, the head base 32 defines in its lower section twolong holes 32a and 32b. The head base 32 is also provided in its uppersection with a pin 32c, which runs vertically through a guide hole 1bformed in the chassis 1 and exits from the rear surface of the chassis1.

As shown in FIG. 7, the selection lever 38 defines two through-holes 38aand 38b, two cam holes 38c and 38d, and a circular hole 38e. Thecircular hole 38e is fitted rotatably on the boss 1a of the chassis 1,and bearings 22 and 23 are fitted in the through-holes 38a and 38b. Thepivots 28 and 29 have their lower ends passing through the long holes32a and 32b, the cam holes 38c and 38d of the selection lever 38 and thecam holes 42a and 43a of the idler levers 42 and 43, and reaching therear surface of the chassis 1. The pivots 28 and 29 are spring biased bythe line spring 35 toward the upper ends of the long holes 32a and 32b.

As shown in FIG. 8, the main motor 2 has its drive shaft extending tothe rear side of the chassis 1, and a pulley 47 is attached on the endof the shaft. Another pulley 48 and two flywheels 49 and 50 are attachedrotatably on the rear surface of the chassis 1, and a belt 51 is aroundthe flywheels 49 and 50 and pulleys 47 and 48. The capstan shafts 20 and21 are fixed at the center of the flywheels 49 and 50, and the flywheels49 and 50 have small gears 49a and 50a and large gears 49b and 50bformed concentrically at the center of the capstan shafts 20 and 21. Thechassis 1 on its rear surface defines two support lugs 1c and 1d, whichsupport shafts 52 and 53, by which the reel bases 36 and 37 are pivoted.

As shown in FIG. 9, one reel base 36 includes a transmission member 91supported rotatably by the shaft 52, a reel gear 56 supported rotatablyby the lower section of the transmission member 91 through a bearing 92,a spring receptacle 93 which is press-fitted in the middle of thetransmission member 91, and a coupling member 54 which is in splineengagement with the upper section of the transmission member 91. Onereel of the cassette tape T couples with the coupling member 54.

The transmission member 91 has on its lower end a disc section 91a, witha rotation detecting disc 58 being on the rear surface thereof. Therotation detecting disc 58 has reflective and non-reflective portionsformed alternately in the circumferentially.

A first spring 94 is fitted between the spring receptacle 93 and thecoupling member 54, by which the coupling member 54 is pushed upward toa washer 95 which stops it. A second spring 96 is fitted between thespring receptacle 93 and the bearing 92, and a slip member 97 made offelt or the like is fitted between the reel gear 56 and the disc section91a of the transmission member 91. The reel gear 56 is pushed by beingintervening slip member 97 to the disc section 91a of the transmissionmember 91 by the downward resilient force of the second spring 96.

Another reel base 37 has the same structure as the reel base 36,although the details are not shown in the figure, and has a couplingmember 55 to be coupled with another reel of the cassette tape T (seeFIG. 5), a reel gear 57, rotation detecting plate 59, etc.

On the rear side of the chassis 1, there are disposed two idler gears 60and 61, and these gears are pivoted by the pivots 44 and 45 on the idlerlevers 42 and 43 and are covered by the flywheels 49 and 50. The idlergears 60 and 61 always engage with the small gears 49a and 50a of theflywheels 49 and 50, and engage with or disengage from the reel gears 56and 57 depending on the operation of the idler levers 42 and 43.

Further disposed on the rear side of the chassis 1 are a positiondetecting lever 62, a lock lever 63, a selection swing 64, and a modeselection lever 65 which covers all or part of these parts. The positiondetecting lever 62 is supported rotatably by a pivot 62c on thechassis 1. The position detecting lever 62 has a pin 62a and athrough-hole 62b, and the pin 32c of the head base 32 runs through theguide hole 1b of the chassis 1 and this through-hole 62b and engageswith a cam hole (explained later) in the mode selection lever 65.

The lock lever 63 has a pin 63a and a stopper 63b, which on one enddefines a small boss 63c as shown in FIG. 14. The lock lever 63 issupported rotatably by a pin 66 on the chassis 1. The selection swing 64is attached rotatably by a pivot 67 on the chassis 1, and it has a pin64a on its upper end. On its lower end, a swing gear 68 is attachedrotatably. The swing gear 68 is located between the reel gears 56 and57, and it engages with one reel gear 56 and the large gear 49b of theflywheel 49, or with another reel gear 57 and the large gear 50b of theflywheel 50 selectively in response to the operation of the selectionswing 64.

As shown in FIG. 10, the mode selection lever 65 defines two guide holes69 and 70 which extend in the longitudinal direction, with the pin 66and another pin 71 being inserted in these guide holes 69 and 70, andthe mode selection lever 65 which is driven by the auxiliary motor 3 isfitted so that it can reciprocate in the right/left direction in FIG. 8relative to the chassis 1. The mode selection lever 65 defines a secondrack 65a in part of its upper edge, a bent formation of a pushing lug65b in one side edge, and a plurality of cam holes 65c-65g in its flatsection.

The cam hole 65c engages the pin 62a of the position detecting lever 62the cam hole 65d engages the pin 63a of the lock lever 63, the cam hole65e engages the pin 32c of the head base 32, the cam hole 65f engagesthe pin 65g of the selection swing 64, and the cam hole 65g engages thepin 41 of the selection arm 39. The cam holes 65c-65g and the respectivepins have their relative positions varied in response to the reciprocalmotion of the mode selection lever 65 for selecting various operationalmodes which will be explained later. The cam hole 65d which engages thepin 63a of the lock lever 63 has a parallel section 65h which extendsalong the moving direction of the mode selection lever 65 and a stepsection 65i which is formed as a continuous end section of the parallelsection 65h to extend in the direction virtually perpendicular to thelever moving direction.

On the rear side of the chassis 1, there is fixed a support plate 72, onwhich a planetary gear mechanism 73, shaft 74 and printed circuit board75 are attached. Two optical sensors 76 and 77 each having a lightemitting element and a light receiving element as a unit are mounted onthe printed circuit board 75. The optical sensors 76 and 77 are locatedto confront the rotation detecting discs 58 and 59, with a certainspacing being provided between them (see FIG. 9). Accordingly, as therotation detecting discs 58 and 59 rotate, the respective opticalsensors 76 and 77 produce pulse signals, and the rotational states ofthe reel gears 56 and 57 are detected based on the pulse signals.Further mounted on the printed circuit board 75 are a tape typeidentifying switch 78 operated by the identifying lever 46, a referenceposition detecting switch 79 operated by the pushing lug 65b of the modeselection lever 65, and a mode detecting switch 80 operated by theposition detecting lever 62.

As shown in FIGS. 12 and 13, the planetary gear mechanism 73 includes asun gear 82 pivoted by a pin 81 standing on the support plate 72, acarrier 83 pivoted by the pin 81, a ring gear 84 fitted rotatably on thecarrier 83, and three planetary gears 85 supported rotatably by pivots83a on the carrier 83. The planetary gears 85 mesh with the inner teeth82a of the sun gear 82 and the inner teeth 84a of the ring gear 84.

The sun gear 82 and ring gear 84 define outer teeth 82b and 84b,respectively, and a gear 86 is press-fitted to the upper end of thecarrier 83. The outer teeth 82b of the sun gear 82 mesh with teeth 87aformed in the lower end of a cylindrical member 87, which is pivoted bythe shaft 74. The cylindrical member 87 protrudes from the upper surfaceof the chassis 1, and teeth 87b formed in its upper end mesh with a wormgear 88 fixed on the drive shaft of the auxiliary motor 3.

The auxiliary motor 3 is attached to the surface of the chassis 1 bybracket 89, and the upper end of the shaft 74 is supported by thebracket 89. The outer teeth 84b of the ring gear 84 mesh with the secondrack 65a of the mode selection lever 65, and the gear 86 fixed to thecarrier 83 runs through an opening 90 formed in the chassis 1 and mesheswith the first rack 10a of the block member 10 on the upper side of thechassis 1.

As shown in FIG. 14, there is formed at the edge of the opening 90 abent section 1e for supporting the upper end of the pin 81. A meshingboss 10b formed on the block member 10 runs through the opening 90 andprotrudes to the rear side of the chassis 1. The first rack 10a of theblock member 10 and the second rack 65a of the mode selection lever 65extend in parallel on both sides of the chassis 1, and the stopper 63bof the lock lever 63 is movable in the opening 90 (within the range ofmotion of the meshing boss 10b of the block member 10).

The sun gear 82 of the planetary gear mechanism 73 serves for the inputshaft, and the carrier 83 and ring gear 84 serve for the output shafts,so that the torque of the auxiliary motor 3 applied to the sun gear 82is transmitted to one of the output shafts (carrier 83 and ring gear 84)depending on the position of the lock lever 63. Specifically, as shownin FIG. 15A, in case the pin 63a of the lock lever 63 engages the step65i of the cam hole 65d, the mode selection lever 65 is stopped by thelock lever 63 and located at the first lock position.

The stopper 63b has its end plane virtually aligned with the tooth tipsof the second rack 65a of the mode selection lever 65 and the blockmember 10 has its meshing boss 10b in contact with a small boss 63c atthe end of the stopper 63b, and therefore the stopper 63b does notrotate in the direction of exposure in the opening 90 and the lock lever63 is retained at the first lock position by the meshing boss 10b. Basedon the press-contact of the meshing boss 10b of the block member 10 tothe small boss 63c of the lock lever 63, the lock lever 63 is preventedfrom having a backlash motion in the rotational direction, and thisprevents the generation of rattle noise even in the presence ofvibration.

In this state, when the auxiliary motor 3 starts rotating, the rotationis transmitted by the worm gear 88 and cylindrical member 87 to the sungear 82 of the planetary gear mechanism 73, and the sun gear 82 rotates.At this time, the ring gear 84 has its outer teeth 84b meshing with thesecond rack 65a of the mode selection lever 65, and it does not rotate.Consequently, the planetary gears 85 spin to go around the pin 81, andthe rotation of the sun gear 82 is transmitted to the carrier 83. As aresult, the carrier 83 and gear 86 rotate in the direction indicated bythe arrow A in FIG. 15A, causing the first rack 10a which meshes withthe gear 86 to move in the direction indicated by the arrow B, and theslide plate 7 attached on the block member 10 also moves in the samedirection.

During the movement of the block member 10 in the direction of arrow B,the meshing boss 10b moves in the opening 90 along the end plane of thestopper 63b, while the lock lever 63 is retained at the first lockposition by the meshing boss 10b, and accordingly the rotation of thelock lever 63 and the movement of the mode selection lever 65 areprecluded. When the meshing boss 10b reaches the end of the opening 90,the block member 10 cannot move any more, and at the same time the locklever 63 cannot rotate freely due to the meshing boss 10b located at thestopper 63b.

In this state, if the auxiliary motor 3 rotates continuously in onedirection, the planetary gears 85 begin to spin since the carrier 83which meshes with the first rack 10a cannot rotate any more, and therotation of the sun gear 82 is transmitted from the ring gear 84 to thesecond rack 65a of the mode selection lever 65. As a result, the ringgear 8 starts rotating in the direction indicated by the arrow C asshown in FIG. 15B, causing a force to act on the mode selection lever 65in the direction indicated by the arrow D, and the pin 63 of the locklever 63 moves from the step 65i to the flat section 65h in the cam hole65d and the lock lever 63 goes around the pin 66 in the clockwise (cw)direction to the second lock position. Consequently, the mode selectionlever 65 starts moving in the direction indicated by the arrow D and, atthe same time, the side end plane of the stopper 63b extends into theopening 90 to mesh with the meshing boss 10b, and the movement of theblock member 10 is precluded by the lock lever 63.

In this manner, during the movement of the mode selection lever 65 inthe direction indicated by the arrow D, the pin 63a of the lock lever 63moves on the flat section 65h of the cam hole 65d, with the lock lever63 being retained at the second lock position by the cam hole 65d duringthis movement, and the rotation of the lock lever 63 and the movement ofthe block member 10 are precluded. When the auxiliary motor 3 rotates inthe opposite direction, the lock lever 63 is switched from the secondlock position to the first lock position, and the foregoing operationstake place in reverse.

As described above, the pin 63a and stopper 63b of the lock lever 63,the cam hole 65d of the mode selection lever 65 and the meshing boss 10bof the block member 10 that is part of the cassette carrying mechanism 4in combination constitute a lock mechanism which selectively precludesthe movement of the cassette carrying mechanism 4 or the mode selectionlever 65.

Next, operation of this cassette tape player is explained.

Initially, a cassette tape T is inserted in the cassette holder 9 of thecassette tape player which is in the state of the end of tape ejectionshown in FIGS. 1 and 3. The slider 19 is pushed in by being hooked bythe reel holes of the cassette tape T, and the first ejection lever 13turns in the counterclockwise (ccw) direction in FIG. 1 against thepulling force of the extension spring 15. The boss on the detectinglever 16 moves in the cam hole 13a, causing the lever 16 to turn in theclockwise (cw) direction, and the cassette insertion detecting switch 18turns on.

Following the turn-on of the cassette insertion detecting switch 18, theauxiliary motor 3 starts rotating in one direction (herein called theforward direction as opposed to the reverse direction), and the cassettecarrying mechanism 4 implements the auto-loading operation. At thistime, the lock lever 63 in its first lock position shown in FIG. 15Aprecludes the movement of the mode selection lever 65, and the forwardrotation of the auxiliary motor 3 is transmitted by the sun gear 82 ofthe planetary gear mechanism 73 and the carrier 83 to the first rack 10awhich meshes with the gear 86 of the carrier 83.

The movement of the first rack 10a moves the block member 10 and slideplate 7 to the left in FIG. 1 (or to the right in FIG. 3). The pin 14aof the second ejection arm 14 moves in the cam hole 7d, causing bothejection arms 13 and 14 to turn in the ccw direction around the pin 12,and the slider 19 slides deep into the plate base 8 along the guidegroove 8c and the cassette tape T is pulled up to the end of thecassette holder 9 as shown in FIG. 2.

The movement of the slide plate 7 causes the roller 8b to move from theupper position to the lower position in the cam hole 7a. Consequently,the plate base 8 turns downward around the shaft 8a, causing thecassette holder 9 to fall to the lower position and loading of thecassette tape T completes.

On completion of loading of the cassette tape T, the meshing boss 10b ofthe block member 10 comes in contact with the end of the opening 90 ofthe chassis 1, causing the slide plate 7 to stop. At this moment, theoutput shaft of the planetary gear mechanism 73 is switched from thecarrier 83 to the ring gear 84, and the rotation of the auxiliary motor3 is transmitted from the ring gear 84 to the second rack 65a of themode selection lever 65. Namely, at the end of loading of the cassettetape T, the lock lever 63 is switched from the first lock position shownin FIG. 15A to the second lock position shown in FIG. 15B, the modeselection lever 65 is moved to the pause position shown in FIG. 16 bythe forward rotation of the auxiliary motor 3, and thereafter it ismoved to one of positions of the operational modes shown in FIGS. 17through 22 by the forward and reverse rotations of the auxiliary motor3.

FIG. 16 shows the pause position of the mode selection lever 65 after ithas moved slightly to the left from the cassette tape loading position.At this position, both idler gears 60 and 61 mesh with the reel gears 56and 57, and the magnetic head 33 is located at the fully retractedposition from the tape of the cassette tape T. After the mode selectionlever 65 has come to the pause position, its pushing lug 65b goes offthe reference position detecting switch 79 on the printed circuit board75, causing the switch 79 to turn on. Then the auxiliary motor 3 stopsbased on the reference position signal released by the switch 79, andthe main motor 2 starts rotating to carry out the tape slack eliminatingoperation.

FIG. 23 is a flowchart showing the control sequence of the slackeliminating operation as carried out by a suitable controller.Initially, the main motor 2 starts rotating at the pause position. Therotation is transmitted by the belt 51 to both flywheels 49 and 50, andfurther transmitted by the idler gears 60 and 61 to both reel gears 56and 57.

Consequently, both reel bases 36 and 37 rotate at a low speed in theirown tape winding directions, causing both reels in engagement with thecoupling members 54 and 55 of the reel bases 36 and 37 to rotate intheir own tape winding directions, and the tape slack between the reelsis eliminated. During rotation of the reel bases 36 and 37, the opticalsensors 76 and 77, which are responsive to the reflective andnon-reflective portions of the rotation detecting discs 58 and 59,output rectangular pulse signals having different duty-cycles.

As shown in FIG. 27, the pulse signals output by the optical sensors 76and 77 are coupled to a pulse width comparator 100, by which the pulsewidths (τ) of the pulse signals are compared to a preset value τ1 storedin the comparator 100. The value of τ1 is determined relative to thereference pulse width τ that would be output by the optical sensors 76and 77 when the reel bases 36 and 37 rotate in a no-load condition.Specifically for the reference pulse width τ of about 47 ms, the presetvalue τ1 is 75 ms.

During the slack elimination, the reel bases 36 and 37, having no tapetension, rotate in virtually the no-load condition, and the rotationdetecting discs 58 and 59 rotate without slipping relative to the reelgears 56 and 57. Accordingly, both optical sensors 76 and 77 outputpulse signals of virtually the same pulse width τ as shown in FIGS. 2Aand 24B. The pulse width τ, which is virtually equal to the pulse widthτ of the no-load condition, is smaller than τ1, and in this case theslack eliminating operation continues.

When the slack has been removed, the tape between the reels creates atension, causing the rotation detecting discs 58 and 59 on thetransmission member 91 to slip against the reel gears 56 and 57, and thepulse width τ of the sensor output signals varies relative to theno-load condition.

In the case of the slack eliminating operation at the middle of thewound tape, in which case both reels have virtually the same amount oftape at the end of slack elimination, the reel bases 36 and 37 coupledto the reels have no difference of winding torque, and therefore therotation detecting discs 58 and 59 stop rotating by slipping against thereel gears 56 and 57. Consequently, the pulse widths T of the pulsesignals from the optical sensors 76 and 77 becomes infinity, i.e., 7<τ1.In response to this transition indicative of the elimination of slack,the pulse width comparator 100 outputs a signal for stopping the mainmotor 2.

In the case of the slack eliminating operation at a tape position closeto one end of the tape, the reel bases 36 and 37 coupled to the reelshave a significant difference in their winding torques depending on theamounts of wound tape at the end of slack elimination. Consequently, therotation detecting disc 58 (or 59) of the reel base 36 (or 37) with thelarger winding torque for the reel with the smaller amount of wound taperotates continuously, whereas the rotation detecting disc 59 (or 58) ofthe reel base 37 (or 36) with the smaller winding torque for the reelwith the larger amount of wound tape is rotated reversely in the tapepay-out direction by slipping.

As a result, the pulse widths of the pulse signals from the opticalsensors 76 ands 77 varies as shown in FIGS. 25A and 25B, with the pulsewidth τ of a reel with the larger amount of wound tape exceeding thepreset value τ1 indicative of the elimination of slack, and the pulsewidth comparator 100 produces a signal for stopping the main motor 2.

FIG. 25A is the waveform of the pulse signal of the reel with thesmaller amount of wound tape, and FIG. 25B is the waveform of the pulsesignal of the reel with the larger amount of wound tape. The pulse widthcomparator 100 is e.g. a microcontroller (not shown).

Judgement of the end of slack elimination is made at the time when thepulse width τ of any of the optical sensors 76 and 77 exceeds the presetvalue τ1 independently of the tape position of the cassette tape T inthe hold position, and the main motor 2 is stopped based on thisjudgement. Accordingly, the slack of tape before the cassette tape T isloaded is eliminated automatically immediately after the cassette tape Tis placed in the hold position.

Since the period of the pulse signals from the optical sensors 76 and 77varies depending on the rotational speed of the rotation detecting discs58 and 59, judgement of the end of slack elimination may be made at atime point when the period τ of the pulse signal of any of the opticalsensors 76 and 77 exceeds the preset value τ1 which is determined fromthe reference period τ0 which is twice the pulse width τ1

On completion of the foregoing slack eliminating operation, theauxiliary motor 3 rotates in the forward direction again, and the modeselection lever 65 is moved from the pause position to the normal playposition shown in FIG. 17. At the same time, the position detectinglever 62 moves by the relative motion of the pin 62a and the cam hole65c, causing the mode detecting switch 80 to operate on and offcyclically depending on the amount of movement of the mode selectionlever 65. After the reference position detecting switch 79 turns on, themicrocontroller counts the on/off operations of the mode detectingswitch 80 so that the mode selection lever 65 moves accurately to acertain operational mode position, i.e., normal play position in thiscase. At the normal play position, the head base 32 advances due to therelative motion of the pin 32c and the cam hole 65e, causing themagnetic head 33 to move to the advanced position where it comes incontact with the tape, and, at the same time, the long holes 32a and 32bof the head base 32 also move to the advanced position.

The selection arm 39 turns due to the relative motion of the pin 41 andthe cam hole 65g, causing the selection lever 38 which couples with theselection arm 39 to turn in the cw direction in FIG. 17 around the boss1a. Consequently, the pivot 29 located on the left in the figure comesin contact with the upper end of the cam hole 43a and the pivot 28located on the right in the figure is moved back by the cam hole 38c ofthe selection lever 38 to come in contact with the bent section of thecam hole 42a, causing one idler gear 61 to mesh with the reel gear 57and another idler gear 60 to separate from the reel gear 56.

After the mode selection lever 65 has reached the normal play position,the auxiliary motor 3 stops and the main motor 2 starts rotating. Therotation is transmitted by the belt 51 to both flywheels 49 and 50.Since the idler gear 60 is disengaged from the reel gear 56, therotation is transmitted by the idler gear 61 only to the reel gear 57,and it rotates at the low speed in the tape winding direction.

The left-hand pinch roller 31 in the figure is pressed onto the capstanshaft 21 through the tape, and the tape is rewound from the supply reel,subjected to the reproduction of recorded information by the magnetichead 33 which is in contact with the tape, and wound on the take-upreel.

The tape runs in the normal direction and when the tape end positioncomes, the coupling member 55 slips against the reel gear 57, causingboth reel bases 36 and 37 to stop rotating, and the auto-reverseoperation will take place. Specifically, the main motor 2 first stopsand the auxiliary motor 3 rotates in the forward direction again causingthe mode selection lever 65 to move from the normal play position to thereverse play position shown in FIG. 18. Consequently, the selection arm39 turns due to the relative motion of the pin and the cam hole 65g andthe selection lever 38 turns in the ccw direction in FIG. 18 around theboss 1 a, causing the pivot 29 on the left in the figure to be movedback by the cam hole 38d of the selection lever 38 and the right-handpivot 28 to advance to the position where it comes in contact with theupper edge of the cam hole 42.

Accordingly, one idler gear 61 separates from the reel gear 57 andanother idler gear 60 meshes with the reel gear 56, as opposed to thenormal play operation.

After the mode selection lever 65 has reached the reverse play position,the auxiliary motor 3 stops and the main motor 2 starts rotating again.The rotation is transmitted by the belt 51 to both flywheels 49 and 50.Since the idler gear 61 is disengaged from the reel gear 57, therotation is transmitted by the idler gear 60 only to the reel gear 56,and it rotates at the low speed in the tape winding direction. The pinchroller 30 is pressed onto the capstan shaft 20 through the tape, and thetape is rewound from the supply reel, fed in the reverse direction, andwound on the take-up reel.

During the foregoing normal play operation or reverse play operation, ifthe REW (rewind) mode is selected, the main motor 2 stops and theauxiliary motor 3 rotates in the reverse direction, causing the modeselection lever 65 to move from the normal play position or reverse playposition to the REW position. For example, when the mode selection lever65 is moved from the normal play position to the REW position shown inFIG. 19, the selection swing 64 turns around the pivot 67 due to therelative motion of the pin 64a and the cam hole 65f, causing the swinggear 68 pivoted by the selection swing 64 to mesh with the reel gear 56and the large gear 49b of the flywheel 49.

The head base 32 retreats slightly due to the relative motion of the pin32c and the cam hole 65e, causing the magnetic head 33 to come in lightcontact with the tape. The pivot 29 located on the left in the figure ismoved back by the cam hole 38d of the selection lever 38, the right-handpivot 28 is retained at the retreat position by the long hole 32a of thehead base 32, and the idler gears 60 and 61 disengage from the reelgears 56 and 57.

When the mode selection lever 65 reaches the REW position, the auxiliarymotor 3 stops and the main motor 2 starts rotating again. The rotationis transmitted by the belt 51 to both flywheels 49 and 50. Since theidler gears 60 and 61 are in disengagement from the reel gears 56 and 57and the swing gear 68 is engaged with the reel gear 56 and the largegear 49b of the flywheel 49, the reel gear 56 rotates in its tapewinding direction and the tape is rewound at the high speed.

FIG. 26 is a flowchart showing the control sequence of the foregoing REWoperation (and FF operation which will be explained later). Initially,the main motor 2 rotates at the low speed, causing the take-up reel base36 to rotate at the usual high speed and the supply reel base 37 alsorotates in the same direction.

Following the commencement of the REW operation, the rotation of thereel bases 36 and 37 is examined based on the pulse signals from theoptical sensors 76 and 77 thereby to judge as to whether the tape is atthe rewind-end position. In the case of the judgement of tape end, theREW operation is terminated, or otherwise the pulse widths of the pulsesignals from the optical sensors 76 and 77 are compared.

The pulse widths of the optical sensors 76 and 77 vary depending on therotational states of the reel bases 36 and 37, as mentioned previously.Specifically, if the REW operation begins when a smaller amount of tapeis wound on the take-up reel than the supply reel, the pulse width τ ofthe optical sensor 76 for the take-up reel base 36 is smaller than thatof the optical sensor 77 for the supply reel 37. In this case, therotation of the main motor 2 is switched to the higher speed, and thetake-up reel base 36 rotates at an extra high speed that is higher thanthe usual high speed. During the REW operation at the extra high speed,if there arises a key input to select other operational mode, e.g.,Normal Play mode, the rotation of the main motor 2 is switched back tothe lower speed and the take-up reel base 36 is slowed down to the usualhigh speed for a certain duration (one second in this embodiment), andthereafter the operation proceeds to the newly selected Normal Playmode.

If, on the other hand, there is no key input for selecting other modeduring the extra high speed REW operation, the main motor 2 rotatescontinuously at that speed until the pulse signals of both opticalsensors 76 and 77 have the same pulse width τ.

In this embodiment, as shown in FIG. 26, as to whether the reel bases 36and 37 stop is detected uninterruptedly even during the extra high speedREW operation, and the REW operation is terminated if both reel bases 36and 37 stop. The reason for this scheme is that during the extra highspeed REW operation, the tape which is being rewound on the take-up reelcan possibly shift progressively in the axial direction and a resultingfrictional force of the tape against the interior surface of thecassette can cause the reel bases 36 and 37 to stop, and unless thestoppage of both reel bases 36 and 37 is detected, the player cannot getout of the extra high speed REW mode and the cassette tape T which is introuble cannot be removed from the player.

In case the REW operation starts, with both reels having virtually thesame amount of wound tape, or when the amounts of wound tape on bothreels become virtually equal during the extra high speed REW operation,the pulse widths of both optical sensors 76 and 77 become equal. In casethe REW operation starts, with the take-up reel having a larger amountof tape than the supply reel, the pulse width of the optical sensor 76becomes greater than that of the optical sensor 77. In these cases wherethe pulse width of the optical sensor 76 for the take-up reel is greaterthan or equal to that of the optical sensor 77 of the supply reel, themain motor 2 rotates continuously at the low speed and the reel base 36for the take-up reel rotates at the usual high speed.

During this usual REW operation, if there arises a key input to selectother operational mode, the operation proceeds to the selected mode, orotherwise the REW operation continues to rewind the whole tape andterminates when the end of tape is detected. For detecting thedifference of rotation of the reel bases 36 and 37 more accurately, thetime lengths of one rotation of the rotation detecting discs 58 and 59may be compared, instead of comparing the pulse widths of the outputpulse signals. On completion of the foregoing REW operation, the modeselection lever 65 is driven by the forward rotation of the auxiliarymotor 3 to move to the normal play position shown in FIG. 17, and thenormal operation is restored.

At this time, although the reel gear 57 for the supply reel tends torotate continuously due to its inertia after the reel gear 56 for thetake-up reel has stopped, it is such that the mode selection lever 65moves to the normal play position by way of the REW brake position atwhich the reel gear 57 for the supply reel is braked, thereby to preventthe slack of tape from occurring. Specifically, when the mode selectionlever 65 has moved slightly (e.g., 2 mm) to the left from the REWposition shown in FIG. 19 and come to the REW brake position shown inFIG. 20, the swing gear 68 separates from the reel gear 56 and the largegear 49b of the flywheel 49 by the turning selection swing 64 and comesback to the center position and, at the same time, the selection lever38 turns in the ccw direction in FIG. 19, causing the left-hand pivot 29to be moved back by the cam hole 38d and one idler gear 61 to mesh withthe reel gear 57. Consequently, at mode switching from the REW operationto the normal play operation, when the reel gear 56 for the take-up reelstops rotating due to the returning to center of the swing gear 68, thereel gear 57 for the supply reel also stops rotating simultaneously dueto plunging of the idler gear 61, and the slack of tape does not occur.

The idler gear 61 rotates continuously in the ccw direction in FIG. 20due to the inertia of the flywheel 50 after the main motor 2 hasstopped. This rotational direction is opposite to the inertia forceacting on the reel gear 57 for the supply reel, and therefore the reelgear 57 rotates slightly in the tape winding direction when the idlergear 61 has meshed with the reel gear 57, and the slack of tape can moresurely be prevented.

In case the FF (fast feed) mode is selected during the normal play orreverse play operation, the main motor 2 stops and the auxiliary motor 3rotates in the reverse direction, causing the mode selection lever 65 tomove from the normal play position or reverse play position to the FFposition. For example, when the mode selection lever 65 moves from thenormal play position to the FF position shown in FIG. 21, the selectionswing 64 turns around the pivot 67 of the selection swing 64 in the cwdirection in the figure, causing the swing gear 68 pivoted by theselection swing 64 to mesh with the left-hand reel gear 57 and the largegear 50b of the flywheel 50. The head base 32 is moved back slightly bythe relative motion of the pin 32c and cam hole 65e, causing themagnetic head 33 to come in light contact with the tape.

The pivots 28 and 29 are moved back by the cam hole 38c of the selectionlever 38 and the long hole 32b of the head base 32, causing the idlergears 60 and 61 to disengage from the reel gears 56 and 57. After themode selection lever 65 has reached the FF position, the auxiliary motor3 stops and the main motor 2 rotates again. The rotation is transmittedby the belt 51 to both flywheels 49 and 50. Since the idler gears 60 and61 are in disengagement from the reel gears 56 and 57 and the swing gear68 is in engagement with the reel gear 57 and the large gear 50bof theflywheel 50, the reel gear 57 rotates in the tape winding direction andthe tape is wound at the high speed in the same direction as the normalplay operation.

The foregoing FF operation is carried out in accordance with the controlsequence shown in the flowchart of FIG. 26. The operation is basicallyidentical to the REW operation, and a detailed explanation is omitted.During the extra high speed FF operation, if there is a key input toselect other operational mode, the rotation of the main motor 2 isswitched from the higher speed to the lower speed, and the take-up reelbase 37 is slowed down to the usual high speed for a certain duration,and thereafter the operation proceeds to the newly selected mode.

On completion of the foregoing FF operation, the mode selection lever 65is moved to the reverse play position shown in FIG. 18 by the forwardrotation of the motor 3, and subsequently the reverse play operationtakes place. In this case, the mode selection lever 65 is moved by wayof the FF brake position to the reverse play position so that the reelgear 56 for the supply reel is braked at the FF brake position therebyto prevent slack in the tape, as in the case of mode switching from theREW operation to the normal play operation explained previously.Specifically, when the mode selection lever 65 has moved slightly (e.g.,2 mm) to the left from the FF position shown in FIG. 21 and come to theFF brake position shown in FIG. 22, the swing gear 68 separates from thereel gear 57 and the large gear 50b of the flywheel 50 by the turningselection swing 64 and comes back to the center position and, at thesame time, the selection lever 38 turns in the cw direction in FIG. 20,causing the right-hand pivot 28 to be moved back by the cam hole 38c andone idler gear 60 to mesh with the reel gear 56. Consequently, at modeswitching from the FF operation to the reverse play operation, when thereel gear 57 for the take-up reel stops rotating due to returning tocenter of the swing gear 68, the reel gear 56 for the supply reel alsostops rotating simultaneously due to plunging of the idler gear 60, andthe slack of tape does not occur.

Also in this case, the reel gear 56 rotates slightly in the tape windingdirection when the idler gear 60 has meshed with the reel gear 56, andthe slack of tape can more surely be prevented.

On completion of any of the foregoing operational modes, if the TapeEject mode is selected, the auxiliary motor 3 rotates in the reversedirection, causing the mode selection lever 65 to move to the pauseposition shown in FIG. 16. At the pause position, the pushing lug 65b ofthe mode selection lever 65 comes in contact with the reference positiondetecting switch 79 on the printed circuit board 75, turning it off.Consequently, the auxiliary motor 3 stops and the main motor 2 rotatesin turn, and the same slack eliminating operation as that at loading ofthe cassette tape T described previously takes place.

Based on this operation, the slack of tape of the cassette tape T in thehold position is eliminated automatically before it is taken out of theplayer, so that the cassette tape T without slack can be loaded nexttime. On completion of the slack eliminating operation, the auxiliarymotor 3 rotates in the reverse direction gain, causing the modeselection lever 65 to move from the pause position to the initialposition of the end of loading of the cassette tape T.

Thereafter, the auto-ejecting operation, which is the reversal of theauto-loading operation described previously, takes place. Specifically,with the cassette tape T being in the hold position, the planetary gearmechanism 73 has its output shaft switched from the ring gear 84 to thecarrier 83. The lock lever 63 moves from the second lock position shownin FIG. 15B to the first lock position shown in FIG. 15A, and the blockmember 10 is moved by the reverse rotation of the auxiliary motor 3.

Consequently, the slide plate 7 moves in the direction opposite to theauto-loading operation to turn the plate base 8 upward, both ejectionarms 13 and 14 turn to slide the slider 19 toward the front of the platebase 8, and the cassette tape T is pushed out of the cassette holder 9.The detecting lever 16 turns in the ccw direction in FIG. 1, causing thecassette insertion detecting switch 18 to turn off, and the auxiliarymotor 3 is stopped to complete the cassette tape ejecting operation.

Besides the foregoing operations, the cassette tape player is switchedfrom the Normal Play, Reverse Play, FF or REW mode to the Pause mode inresponse to the Pause key pressed by the user. Also in this case, themode selection lever 65 moves to the pause position and the slackeliminating operation takes place as described above.

During the operation in any mode, if the power is turned off or if thecount error of the mode detecting switch 80 occurs, the mode selectionlever 65 will return to the cassette tape hold position to turn off thereference position detecting switch 79 when the power is turned on orthe microcontroller is reset. With the mode selection lever 65 beingmoved to the pause position, when the reference position detectingswitch 79 is turned on, an operational mode is selected again based onthe reference position signal released by the switch 79. Accordingly, anawkward procedure for the repetitive mode selection at the time pointwhen the cassette insertion detecting switch 18 turns on following thetemporary ejection of the cassette tape T can be avoided, and thecontrol sequence is simplified.

Although in the foregoing embodiment, the mode selection lever 65 ismoved by the output torque of the ring gear 84 of the planetary gearmechanism 73 and the cassette carrying mechanism is driven by the outputtorque of the carrier 83, the system may be altered such that the ringgear 84 drives the cassette carrying mechanism and the carrier 83 movesthe mode selection lever 65.

According to this invention, as described above, during the cassettetape loading or ejecting operation, the lock mechanism at the first lockposition causes the torque of the drive motor to be transmitted only tothe rack of cassette carrying mechanism by way of one output gear of theplanetary gear mechanism, and the lock mechanism, which is switched tothe second lock position by the rotation of the drive motor during theFF or playback operation, causes the motor torque to be transmitted onlyto the mode selection lever by way of another output gear of theplanetary gear mechanism. Consequently, it is possible for the drivemotor to have its driving gear in steady engagement with the racks ofthe cassette carrying mechanism and mode selection lever through theplanetary gear mechanism, whereby the cassette carrying mechanism andmode selection lever can be driven reliably and noiselessly owing to theelimination of the solenoid operating noise and gear meshing noise, andthe racks of the mode selection lever and cassette carrying mechanismcan have reduced lengths, enabling the cassette tape player to becompact.

I claim:
 1. A cassette tape player having a cassette carrying mechanismwhich conveys a cassette tape between an insertion position and a holdposition of said player automatically, a mode selection lever whichreciprocates depending on operational modes of said player, and a drivemotor which drives said cassette carrying mechanism and said modeselection lever, said player further comprising:a lock mechanism whichselectively prevents movement of said mode selection lever or saidcassette carrying mechanism; and a planetary gear mechanism coupledbetween said drive motor and said mode selection lever and cassettecarrying mechanism and including a sun gear rotated by said drive motor,a ring gear which meshes with one of a first rack provided on said modeselection lever and a second rack provided on said cassette carryingmechanism, and a carrier which meshes with another of said first rackand said second rack, wherein said lock mechanism selectively preventsmovement of said mode selection lever or cassette carrying mechanism sothat the driving force of said drive motor applied to said sun gear isreleased from only one of said ring gear and said carrier.
 2. A cassettetape player according to claim 1, wherein said lock mechanism isswitched to a first position or second position depending on arotational direction of said drive motor when the cassette tape is inthe hold position, and at the first lock position prevents said modeselection lever from moving and at the second lock position preventssaid cassette carrying mechanism from moving.
 3. A cassette tape playeraccording to claim 1, wherein said lock mechanism includes a lock leverwhich moves between a first and second lock positions, said lock leverin said first lock position preventing said mode selection lever frommoving, said lock lever in said second lock position preventing saidcassette carrying mechanism from moving.
 4. A cassette tape playeraccording to claim 3, wherein said mode selection lever, defines a camhole which has a parallel section extending parallel to the movingdirection of said mode selection lever and a step section continuous tothe parallel section and extending in a direction perpendicular to themoving direction of said mode selection lever, a boss on said lock leverbeing inserted into said cam hole, said lock lever moving to said firstlock position when said boss moves from said parallel section to thestep section of said cam hole, thereby preventing said mode selectionlever from moving, said lock lever moving to said second lock positionwhen said boss moves from the step section to said parallel section,thereby allowing said mode selection lever to move.
 5. A cassette tapeplayer according to claim 3, wherein said lock lever has a stoppersection which enters and leaves a moving range of said cassette carryingmechanism, said stopper section being located outside said moving rangeof said cassette carrying mechanism when said lock lever is located atthe first lock position, thereby allowing said cassette carryingmechanism to move, said stopper section being located inside said movingrange of said cassette carrying mechanism when said lock lever islocated at the second lock position, thereby preventing said cassettecarrying mechanism from moving.
 6. A cassette tape player according toclaim 3, wherein said mode selection lever defines a cam hole which hasa parallel section extending in parallel to a moving direction of saidmode selection lever and a step section continuous to said parallelsection and extending in a direction perpendicular to the movingdirection of said mode selection lever, and said lock lever has a bossinserted into said cam hole of said mode selection lever and a stoppersection which can enter or leave a moving range of said cassettecarrying mechanism, said lock lever moving to said first lock positionwhen said boss of said lock lever moves from said parallel section tosaid step section of said cam hole, causing said stopper section toleave said moving range of said cassette carrying mechanism, therebypreventing said mode selection lever from moving and, at the same time,allowing said cassette carrying mechanism to move, said lock levermoving to said second lock position when said boss moves from the stepsection to said parallel section, causing said stopper section to entersaid moving range of said cassette carrying mechanism, thereby allowingsaid mode selection lever to move and preventing said cassette carryingmechanism from moving.
 7. A cassette tape player according to claim 6,wherein said lock lever is pivoted rotatably on a pivot, said boss beinglocated in said parallel section of said cam hole of said mode selectionlever when said lock lever is located at said first lock position,thereby preventing said lock lever from turning, said stopper sectionbeing located outside said moving range of said cassette carryingmechanism and confronting part of said cassette carrying mechanism whichmoves within said moving range when said lock lever is located at saidsecond lock position, thereby preventing said lock lever from turning.8. A cassette tape player according to claim 1, wherein said cassettecarrying mechanism and said mode selection lever are disposed one on afront side and one on a rear side of a generally planar chassis, withsaid first and second racks extending in parallel to each other, andwherein said carrier and said ring gear of said planetary gear mechanismare disposed one on said front side and one on said rear side of saidchassis and are in engagement with said first and second racks,respectively.
 9. A cassette tape player according to claim 1, whereinsaid planetary gear mechanism includes said sun gear which is pivotedrotatably on a pivot and has outer teeth for receiving a drive force ofsaid drive motor on its outer circumference and inner teeth on its innercircumference, said carrier having a gear that meshes with one of saidfirst and second racks and at least one pivot which confronts said innerteeth of said sun gear, and is pivoted rotatably on said pivot, saidring gear being pivoted rotatably on an outer circumference of saidcarrier and having inner teeth which confront said inner teeth of saidsun gear and outer teeth which mesh with another of said first andsecond racks, and a planetary gear which is pivoted rotatably on saidpivot of said carrier and meshes with said inner teeth of said sun gearand said inner teeth of said ring gear.
 10. A cassette tape playerhaving a cassette carrying mechanism which conveys a cassette tapebetween an insertion position and a hold position of said playerautomatically, a mode selection lever which reciprocates depending onoperational modes of such player, and a drive motor which drives saidcassette carrying mechanism and said mode selection lever, said playerfurther comprising:a lock lever which selectively prevents movement ofsaid mode selection lever or said cassette carrying mechanism; and aplanetary gear mechanism coupled between said drive motor and said modeselection lever and cassette carrying mechanism, and including a sungear rotated by said drive motor, a ring gear which meshes with one of afirst rack provided on said mode selection lever and a second rackprovided on said cassette carrying mechanism, and a carrier which mesheswith another of said first rack and said second rack, said lock leverbeing switched to a first position or second position depending on arotational direction of said drive motor when the cassette tape is inthe hold position, and at said first lock position prevents said modeselection lever from moving and at said second lock position preventsaid cassette carrying mechanism from moving.
 11. A cassette tape playeraccording to claim 10, wherein said mode selection lever defines a camhole which has a parallel section extending parallel to a movingdirection of said mode selection lever and a step section continuous tosaid parallel section and extending in a direction perpendicular to saidmoving direction of said mode selection lever, a boss on said lock leverbeing inserted into said cam hole, said lock lever moving to said firstlock position when said boss moves from said parallel section to thestep section of said cam hole, thereby preventing said mode selectionlever from moving, said lock lever moving to said second lock positionwhen said boss moves from said step section to said parallel section,thereby allowing said mode selection lever to move.
 12. A cassette tapeplayer according to claim 10, wherein said lock lever has a stoppersection which can enter or leave a moving range of said cassettecarrying mechanism, said stopper section being located outside saidmoving range of said cassette carrying mechanism when said lock lever islocated at said first lock position, thereby allowing said cassettecarrying mechanism to move, said stopper section being located insidesaid moving range of said cassette carrying mechanism when said locklever is located at said second lock position, thereby preventing saidcassette carrying mechanism from moving.
 13. A cassette tape playeraccording to claim 10, wherein said mode selection lever defines a camhole which has a parallel section extending in parallel to a movingdirection of said mode selection lever and a step section continuous tosaid parallel section and extending in a direction perpendicular to saidmoving direction of said mode selection lever, and said lock lever has aboss which is inserted into said cam hole of said mode selection leverand a stopper section which can enter or leave said moving range of saidcassette carrying mechanism, said lock lever moving to said first lockposition when said boss of said lock lever moves from said parallelsection to said step section of said cam hole of said mode selectionlever, causing said stopper section to leave said moving range of saidcassette carrying mechanism, thereby preventing said mode selectionlever from moving and, at the same time, allowing said cassette carryingmechanism to move, said lock lever moving to said second lock positionwhen said boss moves from said step section to said parallel section ofsaid cam hole, causing said stopper section to enter said moving rangeof said cassette carrying mechanism, thereby allowing said modeselection lever to move and, at the same time, preventing said cassettecarrying mechanism from moving.
 14. A cassette tape player according toclaim 13, wherein said lock lever is pivoted rotatably on a pivot, saidboss being located in said parallel section of said cam hole of saidmode selection lever when said lock lever is located at said first lockposition, thereby preventing said lock lever from turning, said stoppersection being located outside said moving range of said cassettecarrying mechanism and confronting part of said cassette carryingmechanism which moves within said moving range when said lock lever islocated at said second lock position, thereby preventing said lock leverfrom turning.
 15. A cassette tape player according to claim 10, whereinsaid cassette carrying mechanism and said mode selection lever aredisposed one on a front side and one on a rear side of a generallyplanar chassis, with said first and said second racks extending inparallel to each other, and wherein said carrier and said ring gear ofsaid planetary gear mechanism are disposed one on the front side and oneon the rear side of said chassis and are in engagement with said firstand second racks, respectively.
 16. A cassette tape player according toclaim 10, wherein said planetary gear mechanism includes said sun gearwhich is pivoted rotatably on a pivot and has outer teeth for receivinga drive force of said drive motor on its outer circumference and innerteeth on its inner circumference, said carrier having a gear that mesheswith one of said first and said second racks and at least one pivotwhich confronts said inner teeth of said sun gear, and is pivotedrotatably on said pivot, said ring gear being pivoted rotatably on theouter circumference of said carrier and having inner teeth whichconfront said inner teeth of said sun gear and outer teeth which meshwith another of said first and said second racks, and a planetary gearwhich is pivoted rotatably on said pivot of said carrier and meshes withsaid inner teeth of said sun gear and said inner teeth of said ringgear.
 17. A cassette tape player comprising:a cassette carryingmechanism which conveys a cassette tape between an insertion positionand a hold position of said player; a mode selection lever whichreciprocates depending on operational modes of said player and defines acam hole which has a parallel section extending in parallel to a movingdirection of said mode selection lever and a step section continuous tosaid parallel section and extending in a direction perpendicular to amoving direction of said mode selection lever; a drive motor whichdrives said cassette carrying mechanism and said mode selection lever; alock lever which has a boss inserted into said cam hole of said modeselection lever and a stopper section which can enter or leave a movingrange of said cassette carrying mechanism, and selectively prevents themovement of said mode selection lever or said cassette carryingmechanism; and a planetary gear mechanism coupled between said drivemotor and said mode selection lever and cassette carrying mechanism, andincluding a sun gear rotated by said drive motor, a ring gear whichmeshes with one of a first rack provided on said mode selection leverand a second rack provided on said cassette carrying mechanism, and acarrier which meshes with another of said first rack and second rack,wherein said lock lever moves to said first lock position when said bossof said lock lever moves from the parallel section to said step sectionof said cam hole of said mode selection lever, causing said stoppersection of said lock lever to leave said moving range of said cassettecarrying mechanism, thereby preventing said mode selection lever frommoving and allowing said cassette carrying mechanism to move, said locklever moving to said second lock position when said boss moves from thestep section to the parallel section of said cam hole, causing saidstopper section to enter said moving range of said cassette carryingmechanism, thereby allowing said mode selection lever to move andpreventing said cassette carrying mechanism from moving.
 18. A cassettetape player according to claim 17, wherein said lock lever is switchedto a first or second position depending on a rotational direction ofsaid drive motor when said cassette tape is in the hold position.
 19. Acassette tape player according to claim 17, wherein said lock lever ispivoted rotatably on a pivot, said boss being located in said parallelsection of said cam hole of said mode selection lever when said locklever is located at said first lock position, thereby preventing saidlock lever from turning, said stopper section being located outside saidmoving range of said cassette carrying mechanism and confronting part ofsaid cassette carrying mechanism which moves within said moving rangewhen said lock lever is located at said second lock position, therebypreventing said lock lever from turning.
 20. A cassette tape playeraccording to claim 17, wherein said cassette carrying mechanism and saidmode selection lever are disposed one on a front side and one on a rearside of a generally planar chassis, with said first and said secondracks extending in parallel to each other, and wherein said carrier andsaid ring gear of said planetary gear mechanism are disposed one on thefront side and one on the rear side of said chassis and are inengagement with said first and said second racks, respectively.
 21. Acassette tape player according to claim 17, wherein said planetary gearmechanism includes said sun gear which is pivoted rotatably on a pivotand has outer teeth for receiving a drive force of said drive motor onits outer circumference and inner teeth on its inner circumference, saidcarrier having a gear that meshes with one of said first and said secondracks and at least one pivot which confronts said inner teeth of saidsun gear, and is pivoted rotatably on said pivot, said ring gear beingpivoted rotatably on the outer circumference of said carrier and havinginner teeth which confront said inner teeth of said sun gear and outerteeth which mesh with another of said first and said second racks, and aplanetary gear which is pivoted rotatably on said pivot of said carrierand meshes with said inner teeth of said sun gear and said inner teethof said ring gear.